Magnetic sorting and piling bank

ABSTRACT

A device for sorting and stacking lengths of ferromagnetic material, such as rolled steel sections, includes a horizontal conveyor running below magnets. A handling mechanism which can be electromagnets or movable arms or a second conveyor running over a further magnet lifts the steel sections from a mill roller table to the underside of the horizontal conveyor where they are held magnetically. The sections are then carried under the conveyor to a selected position at which a stop is activated to hold the section while the conveyor continues to move. The magnet at that point is then deactivated and the section falls to a receiving surface which may be a partly formed stack of sections. Provision is made for inverting some sections before placing them under the horizontal conveyor where the stack requires the inclusion of inverted sections. The whole operation may be computer controlled.

[ 1 MAGNETIC SORTING AND PILING BANK [75] Inventor: William Petfigrew Cleland, Motherwell, Scotland [73] Assignee: British Steel Corporation, London,

England 22 Filed: Oct. 13, 1971 211 Appl. No.: 188,742

[52] US. Cl ..209/74, 198/41, 198/33 AD,

209/125, 214/105 [51] Int. Cl. ..B07c 3/02 [58] Field of Search ..198/41, 33 AD;

271/63 A; 209/74, 111 B, 125; 214/10.5; 221/18.l, 16, DIG. 3, 64

Primary ExaminerAllen N. Knowles Assistant Examiner-Gene A. Church Attorney-Bacon & Thomas [57] ABSTRACT A device for sorting and stacking lengths of ferromagnetic material, such as rolled steel sections, includes a horizontal conveyor running below magnets. A handling mechanism which can be electromagnets or movable arms or a second conveyor running over a further magnet lifts the steel sections from a mill roller table to the underside of the horizontal conveyor where they are held magnetically. The sections are then carried under the conveyor to a selected position at which a stop is activated to hold the section while the conveyor continues to move. The magnet at that point is then deactivated and the section falls to a receiving surface which may be a partly formed stack of sections. Provision is made for inverting some sections before placing them under the horizontal conveyor where the stack requires the inclusion of inverted sections. The whole operation may be computer controlled.

17 Clains, 5 Drawing Figures -L k/ 20 new PAIENIEMPW v 2.721758 SHEU 1 [IF 4 FIG. 2.

PATENTEUAPRI H975 3, 2 758 SHEET 2 UF 4 FIG. 3.

MAGNETIC SORTING AND FILING BANK This invention relates to a materials handling device, and in particular to apparatus for piling lengths of stackable ferromagnetic material.

The invention is particularly applicable for use in a steel mill producing rolled steel sections, such as angles, channels, bulbs, beams and flats. The final stages in handling these sections involve sorting according to length and/or destination, followed by stacking. Sorting can conventionally be carried out automatically in a computer-controlled mill by stopping the sections at different points along the'final roller table, and pushing the stopped sections sideways off the roller table into a bay adjacent the table at that point. The sections, having been sorted into the various bays, are then stacked.

The present invention provides a method of piling lengths of ferromagnetic material, which method comprises lifting the lengths of material consecutively to the under-surface of a substantially horizontally travelling conveyor, holding the lengths crosswise against the conveyor magnetically and allowing them to travel with the conveyor, arresting each length at a predetermined position above a receiving surface, and removing the magnetic force on the stopped length to allow it to drop to the receiving surface.

The present invention further provides apparatus for piling lengths of ferromagnetic material, comprising a substantially horizontal conveyor movable through first and second stations along a path below a series of contiguous magnets, a mechanism for handling a length of the material and depositing it crosswise on the undersurface of the conveyor atthe first station so that it is magnetically attracted to, and travels with, the conveyor towards the second station, stop means at the second station operable to arrest the material at a selected position and means for de-energizing the magnet at that station whereby to allow the material to drop to a receiving surface.

Where it is intended to stack the lengths, that is to lay a number of successive lengths side by side on the receiving surface and then place further layers on these lengths, the stop means can be movable between different positions along the conveyor, each position being distant from the next by, for example, the width of one length of material. The stop has a continuous range of possible positions above the receiving surface, successive positions being adjusted as necessary having regard to the nature and dimensions of the lengths of material and the type of stack or pile required.

The handling mechanism is preferably magnetic, for example a pair of controlled electromagnets on mechanical arms, and where the lengths of material are rolled steel sections they may pick the section updirectly from the final roller table of the mill. However, some sections such as channels, angles, and bulbs, are conventionally stacked in such a way that some layers of sections are inverted with respect to the remainder, to help keep the stack together or to allow efficient packaging. In a preferred embodiment the apparatus of the invention includes a turnover device adapted to invert selected lengths of material. The turnover device can be a conventional mechanical device incorporated into the roller table, for example pivoted cranked arms to turn over the lengths; or can be incorporated in the handling mechanism, for example by using powered joints in the mechanical arms of the electro-magnetic pick-up means referred to above. However it is preferred that the turnover device should comprise a rotatable magnet, which can suitably be situated with its axis of rotation parallel to, and to one side of and below, the roller table. In this arrangement a selected length is pushed sideways off the roller table and on to the rotatable magnet; rotation of the magnet through about 180 followed by de-energizing the magnet allows the inverted length to be picked up by the ham dling mechanism and deposited on the undersurface of the conveyor.

An alternative form of magnetic handling mechanism comprises a second conveyor movable over a magnet or contiguous magnets between a pick-up station, at which a length of ferromagnetic material can be picked up by the second conveyor, and the first station at the undersurface of the first conveyor, at which the length of ferromagnetic material can be transferred to the first conveyor.

The pick-up station may be on the roller table; it may be necessary to provide mechanical means for ensuring that the length of material on the roller table comes into contact with the second conveyor. At the first station on the first conveyor the strengths of the magnetic fields of the magnets backing the first and second conveyors are chosen to allow transfer of the material from the second to the first conveyor, and to this end the magnet backing the first conveyor will usually have the stronger field at the first station.

The handling mechanism can also be a powerful magnet above the conveyor, lifting the length by magnetic attraction at a distance. However, this is most suitable when the roller table, which normally comprises mostly ferromagnetic material, is replaced by a non-magnetic conveyor. This arrangement is not suited to lengths which require to be inverted before stacking.

The apparatus of the invention preferably comprises a plurality of stop means, each above a corresponding receiving surface and below a corresponding independently controllable magnet. Each stop, with the possible exception of the last downstream stop, can be deactivated, for example by retraction of a stop arm, to allow selected lengths to pass freely above and past the corresponding receiving surface to the next. In this way sorting as well as stacking of the lengths can be accomplished.

The invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a partial side elevation, partly in section, of a sorting-and stacking apparatus;

FIG. 2 is a similar view of part of FIG. 1 in a different operating position; I

FIG. 3 is a side elevation of an alternative turnover device to that shown in FIGS. 1 and 2-,

FIG. 4 is a side elevation of an alternative handling mechanism to that shown in FIG. 1 to 3; and

FIG. 5 is a similar view of part of the apparatus shown in FIG. 4 under different operating conditions.

In FIG. 1 there is shown a conventional steel mill roller table 1 having on it a steel channel section 2. Above the roller table 1 is a conveyor in the form of an endless belt 3 running around a pulley 4 which is motor driven in a clockwise direction as shown. In the down stream direction the belt 3 travels closely beneath permanent magnet 6, control magnet 7, permanent magnet 8, control magnet 9, and permanent magnet 10. The belt may pass beneath further alternate control and permanent magnets before rounding a further pulley and returning to pulley 4 along the upper run. The magnets 6 to 10 are electromagnets arranged with their pole faces downwards and in contact with the upper surface of the lower run of the belt 3. The pole faces have inserts such as nylon to reduce the friction between belt and magnet. Those magnets (6,8,10) referred to as permanent may be permanent magnets as such, or may be el ectromagnets which are continuously energized throughout the operation of the apparatus; while those referred to as control magnets (7,9) can be selectively de-energized as will be described later. Each magnet is designed to be as far as possible effective only over the length of belt immediately below it, and the magnets are arranged contiguously to ensure that material does not drop from the belt in the run between two magnets.

The belt 3 is constructed with an outwardly facing surface which is sufficiently rough to carry the ferromagnetic material past the magnets whose attraction keeps the material on the belt, but sufficiently smooth to allow the material to be arrested by the stops (to be described) while the belt continues to move. The belt 3 preferably does not contain more than a small proportion of ferromagnetic material in its construction, since this material would tend to direct the flux from one magnet along the belt and under an adjacent magnet.

Mounted close to the permanent magnet 6 is a handling mechanism comprising, on the far side of the permanent magnet, an arm 12 fixed on a pivot axle 13, an arm 14 freely pivoted on the arm 12 at 15, and an electromagnet 16 freely pivoted on the arm 14 at 17. A parallel mechanism (not shown) lies on the near side of the permanent magnet 6. The pivot axle 13 is driveable both clock-wise and anticlockwise by a motor (not shown) to allow the magnets 16 to follow parallel arcuate paths.

Associated with control magnet 7 is a pair of stops. One, 20, is shown on the far side of the belt, and a second, parallel stop, not shown in the drawing, lie on the near side of the belt. Each control magnet has a similar pair of stops; thus magnet 9 has stop 21 and a further parallel stop on the near side of the belt. The stops can be positioned at any point along the corresponding control magnet. They can also be adjusted so as to allow material carried on the belt to pass freely; this can be done by raising the stops above the belt or by allowing the material to push the stops up and back on the pivots 22,23.

Below each control magnet is a receiving surface formed on a discharge bogie. Below magnet 7 is a bogie generally designated at 26 having a table 27 which can be hydraulically raised or lowered. The receiving surface is initially the table 27, but as steel sections 28 are stacked on the bogie these sections become the receiving surface. Under the table 27 is a penetration magcourse be de-energized for off-loading from the eventually loaded bogie. A further bogie 29 lies under control magnet 9.

In the operation of the sorting and stacking device shown in FIG. 1, the cold channel section 2 has arrived on the roller table 1 from the mill, which is computer controlled. The section 2 is destined for, say, the bogie 26, for example because on that bogie are stacked sections of that length or the section 2 is destined for a customer whose'order is being assembled on that bogie. The pivot axle 13 rotates clockwise to bring the magnets 16 on to the section 2, the magnets 16 are energized, the axle 13 is driven anti-clockwise causing the magnets 16 to lift the section to the undersurface of the belt 3 beneath the magnet 6, and the magnets 16 are de-energized.

The permanent magnet 6 holds the section on the belt 3. The belt is continuously moving and carries the section downstream. The control magnet 7, which is energized, keeps the section on the belt as it passes away from the influence of permanent magnet 6. The section continues to travel with the belt until it reaches the stop 20.

If the section were destined not for bogie 26 but for bogie 29, or one still further down the belt, the stop 20 would be allowed to pivot freely at 22 and the section would continue travelling until it met a positive stop. In this case, however, the section is to be stacked on bogie 26 and in response to instructions from the computer the stop 20 is locked in position. The section is consequently arrested and slides on the still moving belt 3 at 2 where it is shown in dotted outline.

The instructions from the computer to the stops ensure not only that a section is arrested at the correct control magnet, but that the precise position of the section is controlled to obtain correct stacking. To this end the stops have analogue position control along the length of the control magnets.

The section is allowed to rest at 2' for a short period of time. This allows for alignment of the section with the bogie by ensuring that the section is hard against the stop on each side of the belt. The control magnet 7 is then de-energized and the section drops to its stacking position on the receiving surface.

It has been mentioned that the tables on the bogies can be hydraulically raised and lowered. This is to enable the distance that the sections need to drop to be kept to a minimum. The empty tables are initially raised to the maximum height consistent with avoiding fouling sections passing on the belt, and as the layers of deposited sections build up on the tables the tables are progressively lowered. The tables can be lowered completely when the stack is finished.

It will be appreciated that more than one section can be on the belt at any time, the sections being destined for the same or different bogies. The minimum distance between sections on the belt is determined by the speed of the. belt and the time required to stop a section and deposit it on the receiving surface, as well as on the length of the control magnets. However, for clarity, only one section has been shown travelling in the drawings.

In FIG. 2 there is shown the inversion of a channel section before it is lifted to the belt 3. The section 2 is again shown on the roller table 1. A conventional mill type pusher 31 pushes the section sideways over a bridge 32 to the turnover device shown generally at 33. This turnover device is a rotatable electromagnet comprising an axial core 35 bridging two disc-shaped pole pieces, the nearside one of which is shown at 36. Around the core 35 is a coil 37. The assembly is freely rotatable about its axis except that it can be slowed by a controllable magnetic brake 38 acting on the disc 36.

As the section is pushed on to the turnover device it bridges the two disc pole pieces and held magnetically. Further pushing results in the section passing over the center of the discs, and the weight of the section then causes the assembly to rotate. The magnetic brake 38 is used to slow the rotation to prevent too great an increase in angular momentum. After between one third and one half of a revolution the section then comes up against a stop 40, and is released from the turnover device either by the impact or by de-energizing the coil 37. The section then lies inverted, as shown at 2".

Meanwhile the arms 12 have rotated anticlockwise from the position shown in FIG. 1, and continued rotation brings the magnets 16 into contact with the section at 2". Energizing the magnets 16 and clockwise rotation of the arms 12 picks up the section and brings it up to the belt 3 under the permanent magnet 6, where the magnets 16 are de-energized allowing the inverted section to travel with the belt 3 as before. Subsequent stacking operations are as described with reference to FIG. 1.

The turnover device is linked to the computer control system so that preselected sections are inverted to fit in with the stacking program. The belt 3 may be carrying both inverted and uninverted sections at any one time.

Referring again to FIG. 1, an alternative arrangement of control magnets 7, 9 and permanent magnets 8, is possible. The permanent magnets 8 and 10 can be omitted if the control magnets on each side are extended to meet each other. However, because only one section must be held by a control magnet that is to be de-energized, the greater length of the control magnet means that the minimum permissible distance between sections on the belt is increased. Thus maximum operating rate of the conveyor is reduced.

The turnover device shown in FIGS. 1 and 2 can be replaced by an alternative such as that shown in FIG. 3. A frame 42 carries a rotatable electromagnet shown generally at 43. The electromagnet 43 comprises a core 44 pivotally mounted between two bearing fixed on the frame 42, the near bearing 45 being shown. Fixed to each end of the core 44 are flat pole pieces, the near pole piece 46 being shown. In the rest position of the magnet, shown in FIG. 3 in continuous outline, the pole pieces have a straight horixontal upper edge 48. A stop 49 is fixed to the end of the edge 48 remote from the roller table 1. The electromagnet 43 is rotatably by chain drive from a motor spindle 50.

The turnover device operates as follows. The pusher 31 slides a section 2 from the roller table 1 to bridge the straight edges 48 of the pole pieces 46. The electromagnet is energized and is then rotated about l60 to the position shown in chain dotted outline. The electromagnet is then de-energized, allowing the section to drop, inverted, to the position shown at 2, where it is ready to be raised to the conveyor. The electromagnet 43 is then rotated back to its original position in readiness for any subsequent section.

The alternative handling mechanism shown in FIGS. 4 and 5 may be used with the same steel mill roller table 1, the same conveyor and the same sorting and stacking equipment as shown in FIG. 1. In FIG. 4 are shown the endless belt 3 running around the pulley 4 motor driven in a clockwise direction, the belt 3 travelling in the downstream direction beneath the permanent magnet 6. Downstream of the permanent magnet 6 the apparatus is identical to that shown in FIG. 1.

The alternative handling mechanism comprises a frame carrying pulleys 61 and 62 which in turn carry an endless conveyor belt 63. Further pulleys 65 and 66 carried in the frame serve to maintain the tension of the belt 63. The upper pulley, 61, is above the level of the endless belt 3 of the first conveyor, and the lower pulley, 62, is below the level of the top of the roller table 1. The upper pulley 61 is motor driven in a clockwise direction as shown.

The frame 60 is so positioned that the belt 63 in its upward travel passes adjacent the edge of the roller table 1 and then crosses the path of the endless belt 3. Between these two points the belt 63 is backed by a magnet 67 generally similar to the permanent magnet 6. However, the magnet 67, at the point where it overlaps with the permanent magnet 6, is of less strength than the permanent magnet to facilitate transfer of lengths of ferromagnetic material from the belt 63 to the belt 3.

The upward run of the belt 63 is substantially vertical, that is up to about 5 degrees from the vertical, the upper pulley 61 being inclined slightly over the edge of the roller table 1. The angle the belt 63 makes with the roller table 1 and the belt 3 can however be varied within narrow limits, as the frame 60 can pivot about the axis of pulley 61. The angle is controlled by the hydraulic cylinder 70, which has a piston 71 connected to the frame 60 by lever 72 and linkage 73. Apart from this connection to the cylinder 70, the only support for the frame 60 is given through the axle of motor driven pulley 61.

FIG. 4 shows the handling mechanism raising steel angle sections to the underside of the belt 3 in such a way that when the sections are released from the belt 3 they fall in the same orientation that they were in on the roller table, that is, with the side edges of the sections downwards and the angle uppermost.

The sequence of operations is as follows. A section arrives on the roller table 1 at 75 and is then pushed by a conventional mill type pusher 76 to the position 77 against the belt 63. At this moment the belt 63 is held stationary, and the nearer flat side of the angle section is attracted by the magnet 67 to lie flat against the belt 63. The belt is then restarted and carries the section upwards as shown at 78. Continued upward movement brings the section to position 79 where it comes up against the underside of the moving belt 3; it then transfers in the same orientation to the belt 3, leaving belt 63, and is subsequently carried away as shown at 80 to be sorted and stacked as previously described with reference to FIG. 1.

If the section is to be stacked inverted with respect to its orientation on the roller table 1, the sequence of operations shown in FIG. 5 is followed. A section arrives on the roller table 1 at 83 and is then pushed by the same pusher 76 to the position 84 against the belt 63. Thus far the operations have been identical. However, in this case the belt 63 is not stopped, and a combination of the pressure from the pusher 76, the attraction from magnet 67 and the frictional upward drag from the moving belt results in the leading edge of the angle section being pulled up by the moving belt. The trailing edge is pulled across the roller table towards the belt 63 as the belt rises with the leading edge, until the trailing edge also reaches the belt. The section then rises with the belt as shown at 85. When the section reaches the position 86 its leading edge and subsequently its trailing edge are picked off the belt 63 by the belt 3 and it is then carried by belt 3 as shown at 87. When released by belt 3 over a stack it is in this invented orientation.

Thus to stack a section the same way up as it arrives on the roller table the belt 63 is stopped while the section is picked up, while to stack the section inverted the belt 63 is kept moving while the section is picked up.

This handling mechanism can of course alternatively be used with a septarate. turnover device such as has been previously described.

It will be appreciated that the surface texture of the belt 63 and the strength of the magnet 67 over the distance from the roller table 1 to the belt 3 must be selected to give effective pick-up of the section at the pick-up station and smooth transfer to the undersurface of the first conveyor at its first station while minimizing slip of the section during its passage on the belt 63. A further factor which may require control is the inclination of the belt 63 on its upward run, and the hydraulic cylinder 7V is provided to allow adjustment in this respect. The optimium inclination may in general be about degrees from the vertical, but may not be precisely the same for different sections. Thus we have found that channel sections may more successfully be handled on a more nearly vertical belt than angle sections.

To prevent an undesirable gap appearing between the roller table and the belt 63 during adjustment of the inclination of the belt at least some of the rollers of the roller table can be extended on either side of the belt to overlap with the belt 63.

There will normally be at least one handling mechanism as shown in FIGS. 4 and 5 on each side of the belt 3. Otherwise there would be a danger of lengths with their centers of gravity off the belt 63 swivelling severely out of horizontal and possibly working free from the belt. The handling mechanisms will be interconnected to run at the same speed and lie at the same inclination.

The foregoing description refers to only one conveyor. However it is most useful to have several parallel conveyors, with different spacings between them, so that sections can be carried under at least two conveyors with only a small overhang. Unless the sections are short and the conveyor wide, at least two conveyors should be used for a section. We have found that a suitable arrangement is to use nine parallel conveyors allowing handling of material from feet to 90 feet in length. There are then two bogies spanning the width of the nine-conveyor system; the bogies can be coupled together for handling the longer sections. When short sections are being handled four conveyors on one side of the system can load one bogie, and four on the other side can independently load the second bogie.

If the conveyors are sufficiently long, each may have six control magnets over six bogies. Thus there will be six lines of two bogies under the nine-conveyor system. This allows sorting and stacking of sections on to up to twelve bogies at one time.

When a stack is completed on one bogie, the stack can be lowered on its hydraulic table into the lowest position, and bundled. The bogie can then be run out from under the conveyor system and replaced by an empty bogie. The loaded bogie can be run to a dispatch area and its load removed by crane to storage,

preferably directly to road or rail transport 1 claim:

1. Apparatus for piling lengths of ferromagnetic material, comprising a substantially horizontal conveyor extending between first and second stations, motor means for driving the conveyor from the first to the second stations, at handling mechanism at the first station for raising a length of the ferromagnetic material and depositing it crosswise on the undersurface of the conveyor at the first station so that it is magnetically attracted to and travels with the conveyor towards the second station, said handling mechanism comprising a turnover device adapted to invert selected lengths of material before they are deposited on the undersurface of the conveyor, stop means at the second station operable to arrest the length of ferromagnetic material at a selected position, a receiving surface below the second station, and means for deenergizing the magnet at the second station to allow the stopped length of ferromagnetic material to drop to the receiving surface.

2. Apparatus as claimed in claim 1 wherein the stop means is operable to arrest a length of ferromagnetic material at a position selected from a continuous range of positions at the second station.

3. A combination of two or more of the apparatus as claimed in claim 1 in spaced apart side by side relationship in which each first station lies on a horizontal line perpendicular to the direction of movement of the conveyors and the distances downstream of the first stations to the second stations are similar in each apparatus, the combination including control means whereby the operations of each apparatus can be synchronized.

4. Apparatus as claimed in claim 1 wherein the turnover device comprises a rotatable magnet, means for engaging a length of ferromagnetic material to be inverted with the magnet, means for rotating the magnet about an axis substantially parallel to the length of material, and means for releasing the length of material from the magnet in an inverted orientation.

5. Apparatus as claimed in claim 1 wherein the handling mechanism includes a pair of electromagnets simultaneously movable in parallel paths between a pick-up station in which a length of the material can be engaged by the electromagnets and the first station of the conveyor at which the length of material can be deposited crosswise on the undersurface of the conveyor and released from the electromagnets of the handling mechanism.

6. Apparatus as claimed in claim 1 wherein the handling mechanism comprises a second conveyor movable over a magnet or contiguous magnets between a pick-up station, at which a length of ferromagnetic material can be picked up by the second conveyor, and the first station at the underside of the first conveyor, at which the length of ferromagnetic material can be transferred to the first conveyor.

7. Apparatus as claimed in claim 6 wherein the pickup station is at a table to which successive lengths of ferromagnetic material are delivered and the second conveyor is movable substantially vertically to the first station at the underside of the first conveyor.

8. Apparatus as claimed in claim 6 wherein the handling mechanism is duplicated, whereby one such mechanism is provided on each side of the first conveyor, and the mechanisms are synchronized to operate simultaneously.

9. Apparatus as claimed in claim 1 wherein the conveyor is further movable through subsequent stations along a path below further contiguous magnets, each subsequent station having associated stop means operable to arrest the material at a selected position and the apparatus including means for de-energizing the magnet at that station whereby to allow the material to drop to a receiving surface, each stop means before the last downstream station being further operable to allow passage of selected material through the station with which it is associated.

10. A combination of two or more of the apparatus as claimed in claim 10 in spaced apart side by side relationship in which each first station lies on a horizontal line perpendicular to the direction of movement of the first conveyors and the distances downstream of the first stations to subsequent stations are similar in each apparatus, the combination including control means whereby the operations of each apparatus can be synchronized.

11. Apparatus as claimed in claim 9 wherein the turnover device comprises a rotatable magnet, means for engaging a length of ferromagnetic material to be inverted with the magnet, means for rotating the magnet about an axis substantially parallel to the length of material, and means for releasing the length of material from the magnet in an inverted orientation.

12. Apparatus as claimed in claim 9 wherein the handling mechanism includes a pair of electromagnets simultaneously movable in parallel paths between a pick-up station in which a length of the material can be engaged by the electromagnets and the first station of the conveyor at which the length of material can be deposited crosswise on the undersurface of the conveyor and released from the electromagnets of the handling mechanism.

13. Apparatus as claimed in claim 9 wherein the handling mechanism comprises a second conveyor movable over a magnet or contiguous magnets between a pick-up station, at which a length of ferromagnetic material can be picked up by the second conveyor, and the first station'at the underside of the first conveyor, at which the length of ferromagnetic material can be transferred to the first conveyor.

14. Apparatus as claimed in claim 13 wherein the pick-up station is at a table to which successive lengths of ferromagnetic material are delivered and the second conveyor is movable substantially vertically to the first station at the underside of the first conve or.

15. Apparatus as claimed in claim 1 wherein the handling mechanism is duplicated, whereby one such mechanism is provided on each side of the first conveyor, and the mechanisms are synchronized to operate simultaneously.

16. A method of piling lengths of ferromagnetic material, which method comprises inverting selected lengths of the material, lifting the lengths of the material consecutively to the undersurface of a substantially horizontally travelling conveyor, holding the lengths crosswise against the conveyor magnetically and allowing them to travel with the conveyor, arresting each length at a predetermined position above a receiving surface, and removing the magnetic force on the stopped length to allow it to drop to the receiving surface. 1

17. A method as claimed in claim 16 wherein each length is arrested by a selected one of a plurality of stop means spaced apart lengthwise of the conveyor, each stop means being above a corresponding receiving surface. 

1. Apparatus for piling lengths of ferromagnetic material, comprising a substantially horizontal conveyor extending between first and second stations, motor means for driving the conveyor from the first to the second stations, a handling mechanism at the first station for raising a length of the ferromagnetic material and depositing it crosswise on the undersurface of the conveyor at the first station so that it is magnetically attracted to and travels with the conveyor towards the second station, said handling mechanism comprising a turnover device adapted to invert selected lengths of material before they are deposited on the undersurface of the conveyor, stop means at the second station operable to arrest the length of ferromagnetic material at a selected position, a receiving surface below the second station, and means for deenergizing the magnet at the second station to allow the stopped length of ferromagnetic material to drop to the receiving surface.
 2. Apparatus as claimed in claim 1 wherein the stop means is operable to arrest a length of ferromagnetic material at a position selected from a continuous range of positions at the second station.
 3. A combination of two or more of the apparatus as claimed in claim 1 in spaced apart side by side relationship in which each first station lies on a horizontal line perpendicular to the direction of movement of the conveyors and the distances downstream of the first stations to the second stations are similar in each apparatus, the combination including control means whereby the operations of each apparatus can be synchronized.
 4. Apparatus as claimed in claim 1 wherein the turnover device comprises a rotatable magnet, means for engaging a length of ferromagnetic material to be inverted with the magnet, means for rotating the magnet about an axis substantially parallel to the length of material, and means for releasing the length of material from the magnet in an inverted orientation.
 5. Apparatus as claimEd in claim 1 wherein the handling mechanism includes a pair of electromagnets simultaneously movable in parallel paths between a pick-up station in which a length of the material can be engaged by the electromagnets and the first station of the conveyor at which the length of material can be deposited crosswise on the undersurface of the conveyor and released from the electromagnets of the handling mechanism.
 6. Apparatus as claimed in claim 1 wherein the handling mechanism comprises a second conveyor movable over a magnet or contiguous magnets between a pick-up station, at which a length of ferromagnetic material can be picked up by the second conveyor, and the first station at the underside of the first conveyor, at which the length of ferromagnetic material can be transferred to the first conveyor.
 7. Apparatus as claimed in claim 6 wherein the pick-up station is at a table to which successive lengths of ferromagnetic material are delivered and the second conveyor is movable substantially vertically to the first station at the underside of the first conveyor.
 8. Apparatus as claimed in claim 6 wherein the handling mechanism is duplicated, whereby one such mechanism is provided on each side of the first conveyor, and the mechanisms are synchronized to operate simultaneously.
 9. Apparatus as claimed in claim 1 wherein the conveyor is further movable through subsequent stations along a path below further contiguous magnets, each subsequent station having associated stop means operable to arrest the material at a selected position and the apparatus including means for de-energizing the magnet at that station whereby to allow the material to drop to a receiving surface, each stop means before the last downstream station being further operable to allow passage of selected material through the station with which it is associated.
 10. A combination of two or more of the apparatus as claimed in claim 10 in spaced apart side by side relationship in which each first station lies on a horizontal line perpendicular to the direction of movement of the first conveyors and the distances downstream of the first stations to subsequent stations are similar in each apparatus, the combination including control means whereby the operations of each apparatus can be synchronized.
 11. Apparatus as claimed in claim 9 wherein the turnover device comprises a rotatable magnet, means for engaging a length of ferromagnetic material to be inverted with the magnet, means for rotating the magnet about an axis substantially parallel to the length of material, and means for releasing the length of material from the magnet in an inverted orientation.
 12. Apparatus as claimed in claim 9 wherein the handling mechanism includes a pair of electromagnets simultaneously movable in parallel paths between a pick-up station in which a length of the material can be engaged by the electromagnets and the first station of the conveyor at which the length of material can be deposited crosswise on the undersurface of the conveyor and released from the electromagnets of the handling mechanism.
 13. Apparatus as claimed in claim 9 wherein the handling mechanism comprises a second conveyor movable over a magnet or contiguous magnets between a pick-up station, at which a length of ferromagnetic material can be picked up by the second conveyor, and the first station at the underside of the first conveyor, at which the length of ferromagnetic material can be transferred to the first conveyor.
 14. Apparatus as claimed in claim 13 wherein the pick-up station is at a table to which successive lengths of ferromagnetic material are delivered and the second conveyor is movable substantially vertically to the first station at the underside of the first conveyor.
 15. Apparatus as claimed in claim 13 wherein the handling mechanism is duplicated, whereby one such mechanism is provided on each side of the first conveyor, and the mechanisms are synchronized to operate simultaneously.
 16. A method of piling lEngths of ferromagnetic material, which method comprises inverting selected lengths of the material, lifting the lengths of the material consecutively to the undersurface of a substantially horizontally travelling conveyor, holding the lengths crosswise against the conveyor magnetically and allowing them to travel with the conveyor, arresting each length at a predetermined position above a receiving surface, and removing the magnetic force on the stopped length to allow it to drop to the receiving surface.
 17. A method as claimed in claim 16 wherein each length is arrested by a selected one of a plurality of stop means spaced apart lengthwise of the conveyor, each stop means being above a corresponding receiving surface. 